The present invention relates to an image recording and reproducing apparatus capable of recording and reproducing both of digital signals and analog signals and more particularly to a reference signal necessary to display a state of the image recording and reproducing apparatus in a picture and an operation method of the image recording and reproducing apparatus.
As a domestic apparatus for recording and reproducing image and audio signals, an analog type video tape recorder (hereinafter abbreviated to as VTR) using a magnetic tape is now put to practical use.
On the other hand, a digital television broadcasting begins to be put to practical use as a television broadcasting for the next generation. For example, there is known a system in which the MPEG (Moving Picture Experts Group) system is used to code analog image and audio signals by the high-efficient digital compression code and the coded signals are broadcasted by means of a satellite and coaxial cables. Further, an intelligent receiver and decoder (hereinafter abbreviated to as IRD) which receives digital satellite broadcast and produces analog image and audio signals also begins to be put to practical use.
The above digital broadcasting systems are described in detail in, for example, the Journal of the Institute of Television Engineers of Japan, Vol. 47, No. 4 (1993), pp. 486-503, "5. Broadcasting Service Image".
Furthermore, a VTR which can record and reproduce the digital-compression coded image and audio signals in the digital television broadcasting or the like as the signals are digital and possesses the interchangeability with a current analog VTR is being developed.
Such a VTR which can record and reproduce both of the digital signals and the analog image and audio signals is considered to be configured as shown in, for example, Nikkei Electronics, No. 634, pp. 16-17.
It is not considered that a conventional VTR records such digital broadcast. It is premised that the conventional VTR records image and audio signals supplied by a built-in tuner for receiving analog broadcast. When digital broadcast is recorded, image and audio signals produced by the IRD are inputted from an external input terminals of the VTR to be recorded.
However, the VTR and the IRD are quite independent of each other. For example, in order to preengage to record a program of digital broadcast, it is necessary to set the preengagement in both of the IRD and the VTR. The operation methods of both the apparatuses must be memorized exactly.
Further, many VTRs being currently put on the market includes an on-screen display circuit (hereinafter referred to as OSD circuit) for superimposing information on an analog image signal and an operation state or the like of the VTR can be reported to a user through a picture of a monitoring television (hereinafter abbreviated to as TV). At this time, in order to superimpose information on the analog image, it is necessary to supply a complex synchronization signal which is a reference of the analog image signal to the OSD circuit.
On the other hand, a reference signal inputted to a servo circuit is a complex synchronization signal which is a synchronization signal for an analog image in the case of recording and reproducing of analog signals while the reference signal is a digital synchronization signal outputted by a digital signal processing circuit in the case of recording and reproducing of digital signals. The signal inputted to the servo circuit is different depending on the recording and reproducing times of analog signals and digital signals.
In addition, in the conventional VTR, the servo circuit and the OSD circuit are configured to be supplied with the same reference signal and it is impossible to superimpose information on the image signal upon recording and reproducing of digital signals.